Mark-up languages, such as Hypertext Mark-up Language (HTML) and Extensible Mark-up Language (XML), have been in widespread use for the past several years. Mark-up languages allow software developers to create documents that include a variety of data items, such as text, logos, pictures, and sounds, which can then be rendered by various types of programs, such as web browsers. Mark-up languages use special notations, referred to as tags, to identify data items, and to indicate how the data items are to be processed. These tags also allow computer programs, such as parsers and web browsers, to search, sort, identify and extract data from the document. While mark-up languages make the use and interchange of data easier and more user-configurable, the addition of tags along with the data substantially increases the size of data files. This increase in file size or “bloat” can be considerable, and creates problems when data has to be transmitted quickly or stored compactly.